The working principle of the old BMW 730 heater water valve

The working principle of the heater of the BMW 730 car is as follows: the radiator in the heater is connected to the engine circulating water through the inlet/outlet pipe, and the water valve is a switch: when the water valve is opened, the water line is connected The engine circulating water enters the radiator, and the fan blows the heat into the cab;

BMW 730 car heating water valve maintenance introduction: In seasons when the weather is not cold, you can close the heating air inlet valve to allow The engine cooling system is isolated from the heater valve. In the cold winter, before using the heater, check whether the left and right air supply pipes and the inlet and outlet hoses are loose, falling off, or cracked.

The problem of a broken car heating valve: After raising the temperature, the air coming out of the air outlet is still not hot. The heater cannot be turned off. Even after the temperature is lowered, hot air still comes out of the air outlet. When the air conditioning automatic mode is turned on, the temperature inside the car cannot achieve a constant temperature effect.

Extended information:

The function of the BMW car heating valve is introduced as follows:

The heating valve is actually an electronically controlled valve installed in the heating water tank inlet. Between the water pipe and the small circulation pipe of the engine, the air-conditioning computer controls the opening of the valve, thereby controlling the flow of coolant entering the heater water tank, achieving more precise control of the temperature of the air-conditioner heater.

After the heating water valve fails, the opening of the electronically controlled valve is no longer controlled by the computer and is in a normally open, normally closed or fixed position. At this time, no coolant flows through the warm air water tank or The flow rate is not controlled, and the temperature of the air conditioning warm air is naturally not controlled. If the thermostat is always open, it will also cause the heater to not heat up. After the thermostat is normally open, the coolant circulates widely from the engine idling speed.

Baidu Encyclopedia - Car Heater System

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